One vertex per element, one color per generator, with an edge from x to x·s.
(5,6)(7,11)(8,10)(9,12)(13,14,19,26,18,16,17,21)(15,22,27,20,24,28,25,23)(1,2)(3,4)(5,7)(6,9)(8,12)(10,11) involution — undirected(2,4)(13,15)(14,20)(16,23)(17,27)(18,24)(19,25)(21,28)(22,26) involution — undirected(6,10)(7,12)(13,16,18,14)(15,23,24,20)(17,21,19,26)(22,27,28,25)(15,24)(20,23)(22,28)(25,27) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.